title: Craniocervical hyperpneumatization with concurrent pneumorrhachis, pneumomediastinum, and subcutaneous emphysema in a weightlifter.
abstract: BACKGROUND
  Acquired hyperpneumatization of the skull base and upper cervical vertebrae is extremely rare and is thought to occur in patients who habitually perform the Valsalva maneuver or engage in repetitive positive pressure activities such as scuba diving or free diving. Craniocervical hyperpneumatization has been reported to cause intracranial and extracranial pneumatoceles but is not generally considered as a cause of pneumorrhachis (air in the spinal canal). Pneumorrhachis is relatively rare, and usually occurs in a localized form, either in the cervical spine secondary to skull base fractures or in the thoracic spine secondary to pneumomediastinum or pneumothorax. Here, we report a case of extensive pneumorrhachis extending from the skull base to the thoracolumbar junction in association with marked axio-atlanto-occipital hyperpneumatization and pneumomediastinum. This unique constellation of findings likely resulted from complications of the Valsalva maneuver during strenuous exercise.
  
  
  OBJECTIVE
  To present a unique case of axio-atlanto-occipital hyperpneumatization with concurrent marked cervicothoracic pneumorrhachis, subcutaneous emphysema, and pneumomediastinum and to provide a review of the relevant literature, pathophysiology, and treatment strategies related to hyperpneumatization and pneumorrhachis.
  
  
  METHODS
  A unique case report from an urban medical center.
  
  
  METHODS
  A single case.
  
  
  METHODS
  Imaging findings and clinical history.
  
  
  METHODS
  Imaging data from a picture archiving and communication system and clinical data from an electronic medical record system were analyzed.
  
  
  RESULTS
  A 58-year-old previously healthy man presented with 3 to 4 weeks of neck pain, shoulder pain, and intermittent hand and finger numbness that developed after weightlifting. On physical examination, he had mild hyperreflexia and decreased pinprick sensation within the T5-T8 dermatomes. Initial radiographic and computed tomography (CT) studies demonstrated extensive craniocervical hyperpneumatization involving the occipital bone, clivus, and C1 and C2 vertebral bodies. There was also pneumorrhachis extending throughout the entire cervical and thoracic spine, which caused moderate dural compression. Pneumomediastinum and subcutaneous emphysema were present. Maxillofacial CT showed dehiscent bone involving the dens, atlas, and occipital bone, with adjacent soft-tissue gas and pneumorrhachis. He was managed conservatively and advised to stop performing the Valsalva maneuver during weightlifting. His symptoms resolved, and follow-up imaging showed complete resolution of pneumorrhachis and partial reversal of hyperpneumatization.
  
  
  CONCLUSIONS
  Craniocervical hyperpneumatization is a rare complication of the Valsalva maneuver. Most reported cases have involved only the skull base, or the skull base and C1, and many have been further complicated by microfractures leading to pneumocephalus or extracranial pneumatoceles. We present a unique case of extensive craniocervical hyperpneumatization that extended to the level of C2 and was complicated by microfractures causing severe pneumorrhachis. Concurrent pneumomediastinum in this case may have been an independent complication of the Valsalva maneuver, which could have contributed to pneumorrhachis. Alternatively, pneumomediastinum may have been caused by migration of gas through the neural foramen from the epidural space, driven by positive pressure generated by the one-way valve effect of the Eustachian tube during periods of exertion.
authors.affiliation: Diagnostic Radiology Residency Program, University of Washington, 1959 NE Pacific St, Seattle, WA 98195, USA. Electronic address: germinoj@uw.edu.
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Germino
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Medverd
authors.forename: Vicky T
authors.initials: VT
authors.lastname: Nguyen
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Favinger
authors.forename: Carrie P
authors.initials: CP
authors.lastname: Marder
mesh_terms: D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging; D001270:Cervical Atlas / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008478:Mediastinal Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology; D008875:Middle Aged; D009777:Occipital Bone / Q000000981:diagnostic imaging; D011007:Pneumocephalus / Q000000981:diagnostic imaging* / Q000209:etiology; D063205:Pneumorrhachis / Q000000981:diagnostic imaging* / Q000209:etiology; D011859:Radiography; D013352:Subcutaneous Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology; D014636:Valsalva Maneuver; D014891:Weight Lifting
keywords: Craniocervical pneumatization; Hyperpneumatization; Pneumomediastinum; Pneumorrhachis; Subcutaneous emphysema